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block: Add bdrv_change_backing_file
[qemu/kraxel.git] / block.c
blobc7bc83773a20c5f5c4f9b1bddc0be1e7245dad7e
1 /*
2 * QEMU System Emulator block driver
3 *
4 * Copyright (c) 2003 Fabrice Bellard
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a copy
7 * of this software and associated documentation files (the "Software"), to deal
8 * in the Software without restriction, including without limitation the rights
9 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10 * copies of the Software, and to permit persons to whom the Software is
11 * furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 * THE SOFTWARE.
23 */
24 #include "config-host.h"
25 #include "qemu-common.h"
26 #include "monitor.h"
27 #include "block_int.h"
28 #include "module.h"
29 #include "qemu-objects.h"
30
31 #ifdef CONFIG_BSD
32 #include <sys/types.h>
33 #include <sys/stat.h>
34 #include <sys/ioctl.h>
35 #include <sys/queue.h>
36 #ifndef __DragonFly__
37 #include <sys/disk.h>
38 #endif
39 #endif
40
41 #ifdef _WIN32
42 #include <windows.h>
43 #endif
44
45 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
46 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
47 BlockDriverCompletionFunc *cb, void *opaque);
48 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
49 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
50 BlockDriverCompletionFunc *cb, void *opaque);
51 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
52 BlockDriverCompletionFunc *cb, void *opaque);
53 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
54 uint8_t *buf, int nb_sectors);
55 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
56 const uint8_t *buf, int nb_sectors);
57
58 BlockDriverState *bdrv_first;
59
60 static BlockDriver *first_drv;
61
62 /* If non-zero, use only whitelisted block drivers */
63 static int use_bdrv_whitelist;
64
65 int path_is_absolute(const char *path)
66 {
67 const char *p;
68 #ifdef _WIN32
69 /* specific case for names like: "\\.\d:" */
70 if (*path == '/' || *path == '\\')
71 return 1;
72 #endif
73 p = strchr(path, ':');
74 if (p)
75 p++;
76 else
77 p = path;
78 #ifdef _WIN32
79 return (*p == '/' || *p == '\\');
80 #else
81 return (*p == '/');
82 #endif
83 }
84
85 /* if filename is absolute, just copy it to dest. Otherwise, build a
86 path to it by considering it is relative to base_path. URL are
87 supported. */
88 void path_combine(char *dest, int dest_size,
89 const char *base_path,
90 const char *filename)
91 {
92 const char *p, *p1;
93 int len;
94
95 if (dest_size <= 0)
96 return;
97 if (path_is_absolute(filename)) {
98 pstrcpy(dest, dest_size, filename);
99 } else {
100 p = strchr(base_path, ':');
101 if (p)
102 p++;
103 else
104 p = base_path;
105 p1 = strrchr(base_path, '/');
106 #ifdef _WIN32
107 {
108 const char *p2;
109 p2 = strrchr(base_path, '\\');
110 if (!p1 || p2 > p1)
111 p1 = p2;
112 }
113 #endif
114 if (p1)
115 p1++;
116 else
117 p1 = base_path;
118 if (p1 > p)
119 p = p1;
120 len = p - base_path;
121 if (len > dest_size - 1)
122 len = dest_size - 1;
123 memcpy(dest, base_path, len);
124 dest[len] = '\0';
125 pstrcat(dest, dest_size, filename);
126 }
127 }
128
129 void bdrv_register(BlockDriver *bdrv)
130 {
131 if (!bdrv->bdrv_aio_readv) {
132 /* add AIO emulation layer */
133 bdrv->bdrv_aio_readv = bdrv_aio_readv_em;
134 bdrv->bdrv_aio_writev = bdrv_aio_writev_em;
135 } else if (!bdrv->bdrv_read) {
136 /* add synchronous IO emulation layer */
137 bdrv->bdrv_read = bdrv_read_em;
138 bdrv->bdrv_write = bdrv_write_em;
139 }
140
141 if (!bdrv->bdrv_aio_flush)
142 bdrv->bdrv_aio_flush = bdrv_aio_flush_em;
143
144 bdrv->next = first_drv;
145 first_drv = bdrv;
146 }
147
148 /* create a new block device (by default it is empty) */
149 BlockDriverState *bdrv_new(const char *device_name)
150 {
151 BlockDriverState **pbs, *bs;
152
153 bs = qemu_mallocz(sizeof(BlockDriverState));
154 pstrcpy(bs->device_name, sizeof(bs->device_name), device_name);
155 if (device_name[0] != '\0') {
156 /* insert at the end */
157 pbs = &bdrv_first;
158 while (*pbs != NULL)
159 pbs = &(*pbs)->next;
160 *pbs = bs;
161 }
162 return bs;
163 }
164
165 BlockDriver *bdrv_find_format(const char *format_name)
166 {
167 BlockDriver *drv1;
168 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
169 if (!strcmp(drv1->format_name, format_name))
170 return drv1;
171 }
172 return NULL;
173 }
174
175 static int bdrv_is_whitelisted(BlockDriver *drv)
176 {
177 static const char *whitelist[] = {
178 CONFIG_BDRV_WHITELIST
179 };
180 const char **p;
181
182 if (!whitelist[0])
183 return 1; /* no whitelist, anything goes */
184
185 for (p = whitelist; *p; p++) {
186 if (!strcmp(drv->format_name, *p)) {
187 return 1;
188 }
189 }
190 return 0;
191 }
192
193 BlockDriver *bdrv_find_whitelisted_format(const char *format_name)
194 {
195 BlockDriver *drv = bdrv_find_format(format_name);
196 return drv && bdrv_is_whitelisted(drv) ? drv : NULL;
197 }
198
199 int bdrv_create(BlockDriver *drv, const char* filename,
200 QEMUOptionParameter *options)
201 {
202 if (!drv->bdrv_create)
203 return -ENOTSUP;
204
205 return drv->bdrv_create(filename, options);
206 }
207
208 #ifdef _WIN32
209 void get_tmp_filename(char *filename, int size)
210 {
211 char temp_dir[MAX_PATH];
212
213 GetTempPath(MAX_PATH, temp_dir);
214 GetTempFileName(temp_dir, "qem", 0, filename);
215 }
216 #else
217 void get_tmp_filename(char *filename, int size)
218 {
219 int fd;
220 const char *tmpdir;
221 /* XXX: race condition possible */
222 tmpdir = getenv("TMPDIR");
223 if (!tmpdir)
224 tmpdir = "/tmp";
225 snprintf(filename, size, "%s/vl.XXXXXX", tmpdir);
226 fd = mkstemp(filename);
227 close(fd);
228 }
229 #endif
230
231 #ifdef _WIN32
232 static int is_windows_drive_prefix(const char *filename)
233 {
234 return (((filename[0] >= 'a' && filename[0] <= 'z') ||
235 (filename[0] >= 'A' && filename[0] <= 'Z')) &&
236 filename[1] == ':');
237 }
238
239 int is_windows_drive(const char *filename)
240 {
241 if (is_windows_drive_prefix(filename) &&
242 filename[2] == '\0')
243 return 1;
244 if (strstart(filename, "\\\\.\\", NULL) ||
245 strstart(filename, "//./", NULL))
246 return 1;
247 return 0;
248 }
249 #endif
250
251 static BlockDriver *find_protocol(const char *filename)
252 {
253 BlockDriver *drv1;
254 char protocol[128];
255 int len;
256 const char *p;
257
258 #ifdef _WIN32
259 if (is_windows_drive(filename) ||
260 is_windows_drive_prefix(filename))
261 return bdrv_find_format("raw");
262 #endif
263 p = strchr(filename, ':');
264 if (!p)
265 return bdrv_find_format("raw");
266 len = p - filename;
267 if (len > sizeof(protocol) - 1)
268 len = sizeof(protocol) - 1;
269 memcpy(protocol, filename, len);
270 protocol[len] = '\0';
271 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
272 if (drv1->protocol_name &&
273 !strcmp(drv1->protocol_name, protocol))
274 return drv1;
275 }
276 return NULL;
277 }
278
279 /*
280 * Detect host devices. By convention, /dev/cdrom[N] is always
281 * recognized as a host CDROM.
282 */
283 static BlockDriver *find_hdev_driver(const char *filename)
284 {
285 int score_max = 0, score;
286 BlockDriver *drv = NULL, *d;
287
288 for (d = first_drv; d; d = d->next) {
289 if (d->bdrv_probe_device) {
290 score = d->bdrv_probe_device(filename);
291 if (score > score_max) {
292 score_max = score;
293 drv = d;
294 }
295 }
296 }
297
298 return drv;
299 }
300
301 static BlockDriver *find_image_format(const char *filename)
302 {
303 int ret, score, score_max;
304 BlockDriver *drv1, *drv;
305 uint8_t buf[2048];
306 BlockDriverState *bs;
307
308 drv = find_protocol(filename);
309 /* no need to test disk image formats for vvfat */
310 if (drv && strcmp(drv->format_name, "vvfat") == 0)
311 return drv;
312
313 ret = bdrv_file_open(&bs, filename, BDRV_O_RDONLY);
314 if (ret < 0)
315 return NULL;
316 ret = bdrv_pread(bs, 0, buf, sizeof(buf));
317 bdrv_delete(bs);
318 if (ret < 0) {
319 return NULL;
320 }
321
322 score_max = 0;
323 for(drv1 = first_drv; drv1 != NULL; drv1 = drv1->next) {
324 if (drv1->bdrv_probe) {
325 score = drv1->bdrv_probe(buf, ret, filename);
326 if (score > score_max) {
327 score_max = score;
328 drv = drv1;
329 }
330 }
331 }
332 return drv;
333 }
334
335 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags)
336 {
337 BlockDriverState *bs;
338 int ret;
339
340 bs = bdrv_new("");
341 ret = bdrv_open2(bs, filename, flags | BDRV_O_FILE, NULL);
342 if (ret < 0) {
343 bdrv_delete(bs);
344 return ret;
345 }
346 bs->growable = 1;
347 *pbs = bs;
348 return 0;
349 }
350
351 int bdrv_open(BlockDriverState *bs, const char *filename, int flags)
352 {
353 return bdrv_open2(bs, filename, flags, NULL);
354 }
355
356 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
357 BlockDriver *drv)
358 {
359 int ret, open_flags, try_rw;
360 char tmp_filename[PATH_MAX];
361 char backing_filename[PATH_MAX];
362
363 bs->is_temporary = 0;
364 bs->encrypted = 0;
365 bs->valid_key = 0;
366 /* buffer_alignment defaulted to 512, drivers can change this value */
367 bs->buffer_alignment = 512;
368
369 if (flags & BDRV_O_SNAPSHOT) {
370 BlockDriverState *bs1;
371 int64_t total_size;
372 int is_protocol = 0;
373 BlockDriver *bdrv_qcow2;
374 QEMUOptionParameter *options;
375
376 /* if snapshot, we create a temporary backing file and open it
377 instead of opening 'filename' directly */
378
379 /* if there is a backing file, use it */
380 bs1 = bdrv_new("");
381 ret = bdrv_open2(bs1, filename, 0, drv);
382 if (ret < 0) {
383 bdrv_delete(bs1);
384 return ret;
385 }
386 total_size = bdrv_getlength(bs1) >> BDRV_SECTOR_BITS;
387
388 if (bs1->drv && bs1->drv->protocol_name)
389 is_protocol = 1;
390
391 bdrv_delete(bs1);
392
393 get_tmp_filename(tmp_filename, sizeof(tmp_filename));
394
395 /* Real path is meaningless for protocols */
396 if (is_protocol)
397 snprintf(backing_filename, sizeof(backing_filename),
398 "%s", filename);
399 else if (!realpath(filename, backing_filename))
400 return -errno;
401
402 bdrv_qcow2 = bdrv_find_format("qcow2");
403 options = parse_option_parameters("", bdrv_qcow2->create_options, NULL);
404
405 set_option_parameter_int(options, BLOCK_OPT_SIZE, total_size * 512);
406 set_option_parameter(options, BLOCK_OPT_BACKING_FILE, backing_filename);
407 if (drv) {
408 set_option_parameter(options, BLOCK_OPT_BACKING_FMT,
409 drv->format_name);
410 }
411
412 ret = bdrv_create(bdrv_qcow2, tmp_filename, options);
413 if (ret < 0) {
414 return ret;
415 }
416
417 filename = tmp_filename;
418 drv = bdrv_qcow2;
419 bs->is_temporary = 1;
420 }
421
422 pstrcpy(bs->filename, sizeof(bs->filename), filename);
423 if (flags & BDRV_O_FILE) {
424 drv = find_protocol(filename);
425 } else if (!drv) {
426 drv = find_hdev_driver(filename);
427 if (!drv) {
428 drv = find_image_format(filename);
429 }
430 }
431 if (!drv) {
432 ret = -ENOENT;
433 goto unlink_and_fail;
434 }
435 bs->drv = drv;
436 bs->opaque = qemu_mallocz(drv->instance_size);
437
438 /*
439 * Yes, BDRV_O_NOCACHE aka O_DIRECT means we have to present a
440 * write cache to the guest. We do need the fdatasync to flush
441 * out transactions for block allocations, and we maybe have a
442 * volatile write cache in our backing device to deal with.
443 */
444 if (flags & (BDRV_O_CACHE_WB|BDRV_O_NOCACHE))
445 bs->enable_write_cache = 1;
446
447 /* Note: for compatibility, we open disk image files as RDWR, and
448 RDONLY as fallback */
449 try_rw = !bs->read_only || bs->is_temporary;
450 if (!(flags & BDRV_O_FILE))
451 open_flags = (try_rw ? BDRV_O_RDWR : 0) |
452 (flags & (BDRV_O_CACHE_MASK|BDRV_O_NATIVE_AIO));
453 else
454 open_flags = flags & ~(BDRV_O_FILE | BDRV_O_SNAPSHOT);
455 if (use_bdrv_whitelist && !bdrv_is_whitelisted(drv))
456 ret = -ENOTSUP;
457 else
458 ret = drv->bdrv_open(bs, filename, open_flags);
459 if ((ret == -EACCES || ret == -EPERM) && !(flags & BDRV_O_FILE)) {
460 ret = drv->bdrv_open(bs, filename, open_flags & ~BDRV_O_RDWR);
461 bs->read_only = 1;
462 }
463 if (ret < 0) {
464 qemu_free(bs->opaque);
465 bs->opaque = NULL;
466 bs->drv = NULL;
467 unlink_and_fail:
468 if (bs->is_temporary)
469 unlink(filename);
470 return ret;
471 }
472 if (drv->bdrv_getlength) {
473 bs->total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
474 }
475 #ifndef _WIN32
476 if (bs->is_temporary) {
477 unlink(filename);
478 }
479 #endif
480 if ((flags & BDRV_O_NO_BACKING) == 0 && bs->backing_file[0] != '\0') {
481 /* if there is a backing file, use it */
482 BlockDriver *back_drv = NULL;
483 bs->backing_hd = bdrv_new("");
484 /* pass on read_only property to the backing_hd */
485 bs->backing_hd->read_only = bs->read_only;
486 path_combine(backing_filename, sizeof(backing_filename),
487 filename, bs->backing_file);
488 if (bs->backing_format[0] != '\0')
489 back_drv = bdrv_find_format(bs->backing_format);
490 ret = bdrv_open2(bs->backing_hd, backing_filename, open_flags,
491 back_drv);
492 if (ret < 0) {
493 bdrv_close(bs);
494 return ret;
495 }
496 }
497
498 if (!bdrv_key_required(bs)) {
499 /* call the change callback */
500 bs->media_changed = 1;
501 if (bs->change_cb)
502 bs->change_cb(bs->change_opaque);
503 }
504 return 0;
505 }
506
507 void bdrv_close(BlockDriverState *bs)
508 {
509 if (bs->drv) {
510 if (bs->backing_hd)
511 bdrv_delete(bs->backing_hd);
512 bs->drv->bdrv_close(bs);
513 qemu_free(bs->opaque);
514 #ifdef _WIN32
515 if (bs->is_temporary) {
516 unlink(bs->filename);
517 }
518 #endif
519 bs->opaque = NULL;
520 bs->drv = NULL;
521
522 /* call the change callback */
523 bs->media_changed = 1;
524 if (bs->change_cb)
525 bs->change_cb(bs->change_opaque);
526 }
527 }
528
529 void bdrv_delete(BlockDriverState *bs)
530 {
531 BlockDriverState **pbs;
532
533 pbs = &bdrv_first;
534 while (*pbs != bs && *pbs != NULL)
535 pbs = &(*pbs)->next;
536 if (*pbs == bs)
537 *pbs = bs->next;
538
539 bdrv_close(bs);
540 qemu_free(bs);
541 }
542
543 /*
544 * Run consistency checks on an image
545 *
546 * Returns the number of errors or -errno when an internal error occurs
547 */
548 int bdrv_check(BlockDriverState *bs)
549 {
550 if (bs->drv->bdrv_check == NULL) {
551 return -ENOTSUP;
552 }
553
554 return bs->drv->bdrv_check(bs);
555 }
556
557 /* commit COW file into the raw image */
558 int bdrv_commit(BlockDriverState *bs)
559 {
560 BlockDriver *drv = bs->drv;
561 int64_t i, total_sectors;
562 int n, j;
563 unsigned char sector[512];
564
565 if (!drv)
566 return -ENOMEDIUM;
567
568 if (bs->read_only) {
569 return -EACCES;
570 }
571
572 if (!bs->backing_hd) {
573 return -ENOTSUP;
574 }
575
576 total_sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
577 for (i = 0; i < total_sectors;) {
578 if (drv->bdrv_is_allocated(bs, i, 65536, &n)) {
579 for(j = 0; j < n; j++) {
580 if (bdrv_read(bs, i, sector, 1) != 0) {
581 return -EIO;
582 }
583
584 if (bdrv_write(bs->backing_hd, i, sector, 1) != 0) {
585 return -EIO;
586 }
587 i++;
588 }
589 } else {
590 i += n;
591 }
592 }
593
594 if (drv->bdrv_make_empty)
595 return drv->bdrv_make_empty(bs);
596
597 return 0;
598 }
599
600 /*
601 * Return values:
602 * 0 - success
603 * -EINVAL - backing format specified, but no file
604 * -ENOSPC - can't update the backing file because no space is left in the
605 * image file header
606 * -ENOTSUP - format driver doesn't support changing the backing file
607 */
608 int bdrv_change_backing_file(BlockDriverState *bs,
609 const char *backing_file, const char *backing_fmt)
610 {
611 BlockDriver *drv = bs->drv;
612
613 if (drv->bdrv_change_backing_file != NULL) {
614 return drv->bdrv_change_backing_file(bs, backing_file, backing_fmt);
615 } else {
616 return -ENOTSUP;
617 }
618 }
619
620 static int bdrv_check_byte_request(BlockDriverState *bs, int64_t offset,
621 size_t size)
622 {
623 int64_t len;
624
625 if (!bdrv_is_inserted(bs))
626 return -ENOMEDIUM;
627
628 if (bs->growable)
629 return 0;
630
631 len = bdrv_getlength(bs);
632
633 if (offset < 0)
634 return -EIO;
635
636 if ((offset > len) || (len - offset < size))
637 return -EIO;
638
639 return 0;
640 }
641
642 static int bdrv_check_request(BlockDriverState *bs, int64_t sector_num,
643 int nb_sectors)
644 {
645 return bdrv_check_byte_request(bs, sector_num * 512, nb_sectors * 512);
646 }
647
648 /* return < 0 if error. See bdrv_write() for the return codes */
649 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
650 uint8_t *buf, int nb_sectors)
651 {
652 BlockDriver *drv = bs->drv;
653
654 if (!drv)
655 return -ENOMEDIUM;
656 if (bdrv_check_request(bs, sector_num, nb_sectors))
657 return -EIO;
658
659 return drv->bdrv_read(bs, sector_num, buf, nb_sectors);
660 }
661
662 static void set_dirty_bitmap(BlockDriverState *bs, int64_t sector_num,
663 int nb_sectors, int dirty)
664 {
665 int64_t start, end;
666 unsigned long val, idx, bit;
667
668 start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
669 end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
670
671 for (; start <= end; start++) {
672 idx = start / (sizeof(unsigned long) * 8);
673 bit = start % (sizeof(unsigned long) * 8);
674 val = bs->dirty_bitmap[idx];
675 if (dirty) {
676 val |= 1 << bit;
677 } else {
678 val &= ~(1 << bit);
679 }
680 bs->dirty_bitmap[idx] = val;
681 }
682 }
683
684 /* Return < 0 if error. Important errors are:
685 -EIO generic I/O error (may happen for all errors)
686 -ENOMEDIUM No media inserted.
687 -EINVAL Invalid sector number or nb_sectors
688 -EACCES Trying to write a read-only device
689 */
690 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
691 const uint8_t *buf, int nb_sectors)
692 {
693 BlockDriver *drv = bs->drv;
694 if (!bs->drv)
695 return -ENOMEDIUM;
696 if (bs->read_only)
697 return -EACCES;
698 if (bdrv_check_request(bs, sector_num, nb_sectors))
699 return -EIO;
700
701 if (bs->dirty_bitmap) {
702 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
703 }
704
705 return drv->bdrv_write(bs, sector_num, buf, nb_sectors);
706 }
707
708 int bdrv_pread(BlockDriverState *bs, int64_t offset,
709 void *buf, int count1)
710 {
711 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
712 int len, nb_sectors, count;
713 int64_t sector_num;
714
715 count = count1;
716 /* first read to align to sector start */
717 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
718 if (len > count)
719 len = count;
720 sector_num = offset >> BDRV_SECTOR_BITS;
721 if (len > 0) {
722 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
723 return -EIO;
724 memcpy(buf, tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), len);
725 count -= len;
726 if (count == 0)
727 return count1;
728 sector_num++;
729 buf += len;
730 }
731
732 /* read the sectors "in place" */
733 nb_sectors = count >> BDRV_SECTOR_BITS;
734 if (nb_sectors > 0) {
735 if (bdrv_read(bs, sector_num, buf, nb_sectors) < 0)
736 return -EIO;
737 sector_num += nb_sectors;
738 len = nb_sectors << BDRV_SECTOR_BITS;
739 buf += len;
740 count -= len;
741 }
742
743 /* add data from the last sector */
744 if (count > 0) {
745 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
746 return -EIO;
747 memcpy(buf, tmp_buf, count);
748 }
749 return count1;
750 }
751
752 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
753 const void *buf, int count1)
754 {
755 uint8_t tmp_buf[BDRV_SECTOR_SIZE];
756 int len, nb_sectors, count;
757 int64_t sector_num;
758
759 count = count1;
760 /* first write to align to sector start */
761 len = (BDRV_SECTOR_SIZE - offset) & (BDRV_SECTOR_SIZE - 1);
762 if (len > count)
763 len = count;
764 sector_num = offset >> BDRV_SECTOR_BITS;
765 if (len > 0) {
766 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
767 return -EIO;
768 memcpy(tmp_buf + (offset & (BDRV_SECTOR_SIZE - 1)), buf, len);
769 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
770 return -EIO;
771 count -= len;
772 if (count == 0)
773 return count1;
774 sector_num++;
775 buf += len;
776 }
777
778 /* write the sectors "in place" */
779 nb_sectors = count >> BDRV_SECTOR_BITS;
780 if (nb_sectors > 0) {
781 if (bdrv_write(bs, sector_num, buf, nb_sectors) < 0)
782 return -EIO;
783 sector_num += nb_sectors;
784 len = nb_sectors << BDRV_SECTOR_BITS;
785 buf += len;
786 count -= len;
787 }
788
789 /* add data from the last sector */
790 if (count > 0) {
791 if (bdrv_read(bs, sector_num, tmp_buf, 1) < 0)
792 return -EIO;
793 memcpy(tmp_buf, buf, count);
794 if (bdrv_write(bs, sector_num, tmp_buf, 1) < 0)
795 return -EIO;
796 }
797 return count1;
798 }
799
800 /**
801 * Truncate file to 'offset' bytes (needed only for file protocols)
802 */
803 int bdrv_truncate(BlockDriverState *bs, int64_t offset)
804 {
805 BlockDriver *drv = bs->drv;
806 if (!drv)
807 return -ENOMEDIUM;
808 if (!drv->bdrv_truncate)
809 return -ENOTSUP;
810 if (bs->read_only)
811 return -EACCES;
812 return drv->bdrv_truncate(bs, offset);
813 }
814
815 /**
816 * Length of a file in bytes. Return < 0 if error or unknown.
817 */
818 int64_t bdrv_getlength(BlockDriverState *bs)
819 {
820 BlockDriver *drv = bs->drv;
821 if (!drv)
822 return -ENOMEDIUM;
823 if (!drv->bdrv_getlength) {
824 /* legacy mode */
825 return bs->total_sectors * BDRV_SECTOR_SIZE;
826 }
827 return drv->bdrv_getlength(bs);
828 }
829
830 /* return 0 as number of sectors if no device present or error */
831 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr)
832 {
833 int64_t length;
834 length = bdrv_getlength(bs);
835 if (length < 0)
836 length = 0;
837 else
838 length = length >> BDRV_SECTOR_BITS;
839 *nb_sectors_ptr = length;
840 }
841
842 struct partition {
843 uint8_t boot_ind; /* 0x80 - active */
844 uint8_t head; /* starting head */
845 uint8_t sector; /* starting sector */
846 uint8_t cyl; /* starting cylinder */
847 uint8_t sys_ind; /* What partition type */
848 uint8_t end_head; /* end head */
849 uint8_t end_sector; /* end sector */
850 uint8_t end_cyl; /* end cylinder */
851 uint32_t start_sect; /* starting sector counting from 0 */
852 uint32_t nr_sects; /* nr of sectors in partition */
853 } __attribute__((packed));
854
855 /* try to guess the disk logical geometry from the MSDOS partition table. Return 0 if OK, -1 if could not guess */
856 static int guess_disk_lchs(BlockDriverState *bs,
857 int *pcylinders, int *pheads, int *psectors)
858 {
859 uint8_t buf[512];
860 int ret, i, heads, sectors, cylinders;
861 struct partition *p;
862 uint32_t nr_sects;
863 uint64_t nb_sectors;
864
865 bdrv_get_geometry(bs, &nb_sectors);
866
867 ret = bdrv_read(bs, 0, buf, 1);
868 if (ret < 0)
869 return -1;
870 /* test msdos magic */
871 if (buf[510] != 0x55 || buf[511] != 0xaa)
872 return -1;
873 for(i = 0; i < 4; i++) {
874 p = ((struct partition *)(buf + 0x1be)) + i;
875 nr_sects = le32_to_cpu(p->nr_sects);
876 if (nr_sects && p->end_head) {
877 /* We make the assumption that the partition terminates on
878 a cylinder boundary */
879 heads = p->end_head + 1;
880 sectors = p->end_sector & 63;
881 if (sectors == 0)
882 continue;
883 cylinders = nb_sectors / (heads * sectors);
884 if (cylinders < 1 || cylinders > 16383)
885 continue;
886 *pheads = heads;
887 *psectors = sectors;
888 *pcylinders = cylinders;
889 #if 0
890 printf("guessed geometry: LCHS=%d %d %d\n",
891 cylinders, heads, sectors);
892 #endif
893 return 0;
894 }
895 }
896 return -1;
897 }
898
899 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs)
900 {
901 int translation, lba_detected = 0;
902 int cylinders, heads, secs;
903 uint64_t nb_sectors;
904
905 /* if a geometry hint is available, use it */
906 bdrv_get_geometry(bs, &nb_sectors);
907 bdrv_get_geometry_hint(bs, &cylinders, &heads, &secs);
908 translation = bdrv_get_translation_hint(bs);
909 if (cylinders != 0) {
910 *pcyls = cylinders;
911 *pheads = heads;
912 *psecs = secs;
913 } else {
914 if (guess_disk_lchs(bs, &cylinders, &heads, &secs) == 0) {
915 if (heads > 16) {
916 /* if heads > 16, it means that a BIOS LBA
917 translation was active, so the default
918 hardware geometry is OK */
919 lba_detected = 1;
920 goto default_geometry;
921 } else {
922 *pcyls = cylinders;
923 *pheads = heads;
924 *psecs = secs;
925 /* disable any translation to be in sync with
926 the logical geometry */
927 if (translation == BIOS_ATA_TRANSLATION_AUTO) {
928 bdrv_set_translation_hint(bs,
929 BIOS_ATA_TRANSLATION_NONE);
930 }
931 }
932 } else {
933 default_geometry:
934 /* if no geometry, use a standard physical disk geometry */
935 cylinders = nb_sectors / (16 * 63);
936
937 if (cylinders > 16383)
938 cylinders = 16383;
939 else if (cylinders < 2)
940 cylinders = 2;
941 *pcyls = cylinders;
942 *pheads = 16;
943 *psecs = 63;
944 if ((lba_detected == 1) && (translation == BIOS_ATA_TRANSLATION_AUTO)) {
945 if ((*pcyls * *pheads) <= 131072) {
946 bdrv_set_translation_hint(bs,
947 BIOS_ATA_TRANSLATION_LARGE);
948 } else {
949 bdrv_set_translation_hint(bs,
950 BIOS_ATA_TRANSLATION_LBA);
951 }
952 }
953 }
954 bdrv_set_geometry_hint(bs, *pcyls, *pheads, *psecs);
955 }
956 }
957
958 void bdrv_set_geometry_hint(BlockDriverState *bs,
959 int cyls, int heads, int secs)
960 {
961 bs->cyls = cyls;
962 bs->heads = heads;
963 bs->secs = secs;
964 }
965
966 void bdrv_set_type_hint(BlockDriverState *bs, int type)
967 {
968 bs->type = type;
969 bs->removable = ((type == BDRV_TYPE_CDROM ||
970 type == BDRV_TYPE_FLOPPY));
971 }
972
973 void bdrv_set_translation_hint(BlockDriverState *bs, int translation)
974 {
975 bs->translation = translation;
976 }
977
978 void bdrv_get_geometry_hint(BlockDriverState *bs,
979 int *pcyls, int *pheads, int *psecs)
980 {
981 *pcyls = bs->cyls;
982 *pheads = bs->heads;
983 *psecs = bs->secs;
984 }
985
986 int bdrv_get_type_hint(BlockDriverState *bs)
987 {
988 return bs->type;
989 }
990
991 int bdrv_get_translation_hint(BlockDriverState *bs)
992 {
993 return bs->translation;
994 }
995
996 int bdrv_is_removable(BlockDriverState *bs)
997 {
998 return bs->removable;
999 }
1000
1001 int bdrv_is_read_only(BlockDriverState *bs)
1002 {
1003 return bs->read_only;
1004 }
1005
1006 int bdrv_set_read_only(BlockDriverState *bs, int read_only)
1007 {
1008 int ret = bs->read_only;
1009 bs->read_only = read_only;
1010 return ret;
1011 }
1012
1013 int bdrv_is_sg(BlockDriverState *bs)
1014 {
1015 return bs->sg;
1016 }
1017
1018 int bdrv_enable_write_cache(BlockDriverState *bs)
1019 {
1020 return bs->enable_write_cache;
1021 }
1022
1023 /* XXX: no longer used */
1024 void bdrv_set_change_cb(BlockDriverState *bs,
1025 void (*change_cb)(void *opaque), void *opaque)
1026 {
1027 bs->change_cb = change_cb;
1028 bs->change_opaque = opaque;
1029 }
1030
1031 int bdrv_is_encrypted(BlockDriverState *bs)
1032 {
1033 if (bs->backing_hd && bs->backing_hd->encrypted)
1034 return 1;
1035 return bs->encrypted;
1036 }
1037
1038 int bdrv_key_required(BlockDriverState *bs)
1039 {
1040 BlockDriverState *backing_hd = bs->backing_hd;
1041
1042 if (backing_hd && backing_hd->encrypted && !backing_hd->valid_key)
1043 return 1;
1044 return (bs->encrypted && !bs->valid_key);
1045 }
1046
1047 int bdrv_set_key(BlockDriverState *bs, const char *key)
1048 {
1049 int ret;
1050 if (bs->backing_hd && bs->backing_hd->encrypted) {
1051 ret = bdrv_set_key(bs->backing_hd, key);
1052 if (ret < 0)
1053 return ret;
1054 if (!bs->encrypted)
1055 return 0;
1056 }
1057 if (!bs->encrypted || !bs->drv || !bs->drv->bdrv_set_key)
1058 return -1;
1059 ret = bs->drv->bdrv_set_key(bs, key);
1060 if (ret < 0) {
1061 bs->valid_key = 0;
1062 } else if (!bs->valid_key) {
1063 bs->valid_key = 1;
1064 /* call the change callback now, we skipped it on open */
1065 bs->media_changed = 1;
1066 if (bs->change_cb)
1067 bs->change_cb(bs->change_opaque);
1068 }
1069 return ret;
1070 }
1071
1072 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size)
1073 {
1074 if (!bs->drv) {
1075 buf[0] = '\0';
1076 } else {
1077 pstrcpy(buf, buf_size, bs->drv->format_name);
1078 }
1079 }
1080
1081 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
1082 void *opaque)
1083 {
1084 BlockDriver *drv;
1085
1086 for (drv = first_drv; drv != NULL; drv = drv->next) {
1087 it(opaque, drv->format_name);
1088 }
1089 }
1090
1091 BlockDriverState *bdrv_find(const char *name)
1092 {
1093 BlockDriverState *bs;
1094
1095 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1096 if (!strcmp(name, bs->device_name))
1097 return bs;
1098 }
1099 return NULL;
1100 }
1101
1102 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs), void *opaque)
1103 {
1104 BlockDriverState *bs;
1105
1106 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1107 it(opaque, bs);
1108 }
1109 }
1110
1111 const char *bdrv_get_device_name(BlockDriverState *bs)
1112 {
1113 return bs->device_name;
1114 }
1115
1116 void bdrv_flush(BlockDriverState *bs)
1117 {
1118 if (!bs->drv)
1119 return;
1120 if (bs->drv->bdrv_flush)
1121 bs->drv->bdrv_flush(bs);
1122 if (bs->backing_hd)
1123 bdrv_flush(bs->backing_hd);
1124 }
1125
1126 void bdrv_flush_all(void)
1127 {
1128 BlockDriverState *bs;
1129
1130 for (bs = bdrv_first; bs != NULL; bs = bs->next)
1131 if (bs->drv && !bdrv_is_read_only(bs) &&
1132 (!bdrv_is_removable(bs) || bdrv_is_inserted(bs)))
1133 bdrv_flush(bs);
1134 }
1135
1136 /*
1137 * Returns true iff the specified sector is present in the disk image. Drivers
1138 * not implementing the functionality are assumed to not support backing files,
1139 * hence all their sectors are reported as allocated.
1140 *
1141 * 'pnum' is set to the number of sectors (including and immediately following
1142 * the specified sector) that are known to be in the same
1143 * allocated/unallocated state.
1144 *
1145 * 'nb_sectors' is the max value 'pnum' should be set to.
1146 */
1147 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
1148 int *pnum)
1149 {
1150 int64_t n;
1151 if (!bs->drv->bdrv_is_allocated) {
1152 if (sector_num >= bs->total_sectors) {
1153 *pnum = 0;
1154 return 0;
1155 }
1156 n = bs->total_sectors - sector_num;
1157 *pnum = (n < nb_sectors) ? (n) : (nb_sectors);
1158 return 1;
1159 }
1160 return bs->drv->bdrv_is_allocated(bs, sector_num, nb_sectors, pnum);
1161 }
1162
1163 static void bdrv_print_dict(QObject *obj, void *opaque)
1164 {
1165 QDict *bs_dict;
1166 Monitor *mon = opaque;
1167
1168 bs_dict = qobject_to_qdict(obj);
1169
1170 monitor_printf(mon, "%s: type=%s removable=%d",
1171 qdict_get_str(bs_dict, "device"),
1172 qdict_get_str(bs_dict, "type"),
1173 qdict_get_bool(bs_dict, "removable"));
1174
1175 if (qdict_get_bool(bs_dict, "removable")) {
1176 monitor_printf(mon, " locked=%d", qdict_get_bool(bs_dict, "locked"));
1177 }
1178
1179 if (qdict_haskey(bs_dict, "inserted")) {
1180 QDict *qdict = qobject_to_qdict(qdict_get(bs_dict, "inserted"));
1181
1182 monitor_printf(mon, " file=");
1183 monitor_print_filename(mon, qdict_get_str(qdict, "file"));
1184 if (qdict_haskey(qdict, "backing_file")) {
1185 monitor_printf(mon, " backing_file=");
1186 monitor_print_filename(mon, qdict_get_str(qdict, "backing_file"));
1187 }
1188 monitor_printf(mon, " ro=%d drv=%s encrypted=%d",
1189 qdict_get_bool(qdict, "ro"),
1190 qdict_get_str(qdict, "drv"),
1191 qdict_get_bool(qdict, "encrypted"));
1192 } else {
1193 monitor_printf(mon, " [not inserted]");
1194 }
1195
1196 monitor_printf(mon, "\n");
1197 }
1198
1199 void bdrv_info_print(Monitor *mon, const QObject *data)
1200 {
1201 qlist_iter(qobject_to_qlist(data), bdrv_print_dict, mon);
1202 }
1203
1204 /**
1205 * bdrv_info(): Block devices information
1206 *
1207 * Each block device information is stored in a QDict and the
1208 * returned QObject is a QList of all devices.
1209 *
1210 * The QDict contains the following:
1211 *
1212 * - "device": device name
1213 * - "type": device type
1214 * - "removable": true if the device is removable, false otherwise
1215 * - "locked": true if the device is locked, false otherwise
1216 * - "inserted": only present if the device is inserted, it is a QDict
1217 * containing the following:
1218 * - "file": device file name
1219 * - "ro": true if read-only, false otherwise
1220 * - "drv": driver format name
1221 * - "backing_file": backing file name if one is used
1222 * - "encrypted": true if encrypted, false otherwise
1223 *
1224 * Example:
1225 *
1226 * [ { "device": "ide0-hd0", "type": "hd", "removable": false, "locked": false,
1227 * "inserted": { "file": "/tmp/foobar", "ro": false, "drv": "qcow2" } },
1228 * { "device": "floppy0", "type": "floppy", "removable": true,
1229 * "locked": false } ]
1230 */
1231 void bdrv_info(Monitor *mon, QObject **ret_data)
1232 {
1233 QList *bs_list;
1234 BlockDriverState *bs;
1235
1236 bs_list = qlist_new();
1237
1238 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1239 QObject *bs_obj;
1240 const char *type = "unknown";
1241
1242 switch(bs->type) {
1243 case BDRV_TYPE_HD:
1244 type = "hd";
1245 break;
1246 case BDRV_TYPE_CDROM:
1247 type = "cdrom";
1248 break;
1249 case BDRV_TYPE_FLOPPY:
1250 type = "floppy";
1251 break;
1252 }
1253
1254 bs_obj = qobject_from_jsonf("{ 'device': %s, 'type': %s, "
1255 "'removable': %i, 'locked': %i }",
1256 bs->device_name, type, bs->removable,
1257 bs->locked);
1258 assert(bs_obj != NULL);
1259
1260 if (bs->drv) {
1261 QObject *obj;
1262 QDict *bs_dict = qobject_to_qdict(bs_obj);
1263
1264 obj = qobject_from_jsonf("{ 'file': %s, 'ro': %i, 'drv': %s, "
1265 "'encrypted': %i }",
1266 bs->filename, bs->read_only,
1267 bs->drv->format_name,
1268 bdrv_is_encrypted(bs));
1269 assert(obj != NULL);
1270 if (bs->backing_file[0] != '\0') {
1271 QDict *qdict = qobject_to_qdict(obj);
1272 qdict_put(qdict, "backing_file",
1273 qstring_from_str(bs->backing_file));
1274 }
1275
1276 qdict_put_obj(bs_dict, "inserted", obj);
1277 }
1278 qlist_append_obj(bs_list, bs_obj);
1279 }
1280
1281 *ret_data = QOBJECT(bs_list);
1282 }
1283
1284 static void bdrv_stats_iter(QObject *data, void *opaque)
1285 {
1286 QDict *qdict;
1287 Monitor *mon = opaque;
1288
1289 qdict = qobject_to_qdict(data);
1290 monitor_printf(mon, "%s:", qdict_get_str(qdict, "device"));
1291
1292 qdict = qobject_to_qdict(qdict_get(qdict, "stats"));
1293 monitor_printf(mon, " rd_bytes=%" PRId64
1294 " wr_bytes=%" PRId64
1295 " rd_operations=%" PRId64
1296 " wr_operations=%" PRId64
1297 "\n",
1298 qdict_get_int(qdict, "rd_bytes"),
1299 qdict_get_int(qdict, "wr_bytes"),
1300 qdict_get_int(qdict, "rd_operations"),
1301 qdict_get_int(qdict, "wr_operations"));
1302 }
1303
1304 void bdrv_stats_print(Monitor *mon, const QObject *data)
1305 {
1306 qlist_iter(qobject_to_qlist(data), bdrv_stats_iter, mon);
1307 }
1308
1309 /**
1310 * bdrv_info_stats(): show block device statistics
1311 *
1312 * Each device statistic information is stored in a QDict and
1313 * the returned QObject is a QList of all devices.
1314 *
1315 * The QDict contains the following:
1316 *
1317 * - "device": device name
1318 * - "stats": A QDict with the statistics information, it contains:
1319 * - "rd_bytes": bytes read
1320 * - "wr_bytes": bytes written
1321 * - "rd_operations": read operations
1322 * - "wr_operations": write operations
1323 *
1324 * Example:
1325 *
1326 * [ { "device": "ide0-hd0",
1327 * "stats": { "rd_bytes": 512,
1328 * "wr_bytes": 0,
1329 * "rd_operations": 1,
1330 * "wr_operations": 0 } },
1331 * { "device": "ide1-cd0",
1332 * "stats": { "rd_bytes": 0,
1333 * "wr_bytes": 0,
1334 * "rd_operations": 0,
1335 * "wr_operations": 0 } } ]
1336 */
1337 void bdrv_info_stats(Monitor *mon, QObject **ret_data)
1338 {
1339 QObject *obj;
1340 QList *devices;
1341 BlockDriverState *bs;
1342
1343 devices = qlist_new();
1344
1345 for (bs = bdrv_first; bs != NULL; bs = bs->next) {
1346 obj = qobject_from_jsonf("{ 'device': %s, 'stats': {"
1347 "'rd_bytes': %" PRId64 ","
1348 "'wr_bytes': %" PRId64 ","
1349 "'rd_operations': %" PRId64 ","
1350 "'wr_operations': %" PRId64
1351 "} }",
1352 bs->device_name,
1353 bs->rd_bytes, bs->wr_bytes,
1354 bs->rd_ops, bs->wr_ops);
1355 assert(obj != NULL);
1356 qlist_append_obj(devices, obj);
1357 }
1358
1359 *ret_data = QOBJECT(devices);
1360 }
1361
1362 const char *bdrv_get_encrypted_filename(BlockDriverState *bs)
1363 {
1364 if (bs->backing_hd && bs->backing_hd->encrypted)
1365 return bs->backing_file;
1366 else if (bs->encrypted)
1367 return bs->filename;
1368 else
1369 return NULL;
1370 }
1371
1372 void bdrv_get_backing_filename(BlockDriverState *bs,
1373 char *filename, int filename_size)
1374 {
1375 if (!bs->backing_file) {
1376 pstrcpy(filename, filename_size, "");
1377 } else {
1378 pstrcpy(filename, filename_size, bs->backing_file);
1379 }
1380 }
1381
1382 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
1383 const uint8_t *buf, int nb_sectors)
1384 {
1385 BlockDriver *drv = bs->drv;
1386 if (!drv)
1387 return -ENOMEDIUM;
1388 if (!drv->bdrv_write_compressed)
1389 return -ENOTSUP;
1390 if (bdrv_check_request(bs, sector_num, nb_sectors))
1391 return -EIO;
1392
1393 if (bs->dirty_bitmap) {
1394 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1395 }
1396
1397 return drv->bdrv_write_compressed(bs, sector_num, buf, nb_sectors);
1398 }
1399
1400 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi)
1401 {
1402 BlockDriver *drv = bs->drv;
1403 if (!drv)
1404 return -ENOMEDIUM;
1405 if (!drv->bdrv_get_info)
1406 return -ENOTSUP;
1407 memset(bdi, 0, sizeof(*bdi));
1408 return drv->bdrv_get_info(bs, bdi);
1409 }
1410
1411 int bdrv_save_vmstate(BlockDriverState *bs, const uint8_t *buf,
1412 int64_t pos, int size)
1413 {
1414 BlockDriver *drv = bs->drv;
1415 if (!drv)
1416 return -ENOMEDIUM;
1417 if (!drv->bdrv_save_vmstate)
1418 return -ENOTSUP;
1419 return drv->bdrv_save_vmstate(bs, buf, pos, size);
1420 }
1421
1422 int bdrv_load_vmstate(BlockDriverState *bs, uint8_t *buf,
1423 int64_t pos, int size)
1424 {
1425 BlockDriver *drv = bs->drv;
1426 if (!drv)
1427 return -ENOMEDIUM;
1428 if (!drv->bdrv_load_vmstate)
1429 return -ENOTSUP;
1430 return drv->bdrv_load_vmstate(bs, buf, pos, size);
1431 }
1432
1433 /**************************************************************/
1434 /* handling of snapshots */
1435
1436 int bdrv_snapshot_create(BlockDriverState *bs,
1437 QEMUSnapshotInfo *sn_info)
1438 {
1439 BlockDriver *drv = bs->drv;
1440 if (!drv)
1441 return -ENOMEDIUM;
1442 if (!drv->bdrv_snapshot_create)
1443 return -ENOTSUP;
1444 return drv->bdrv_snapshot_create(bs, sn_info);
1445 }
1446
1447 int bdrv_snapshot_goto(BlockDriverState *bs,
1448 const char *snapshot_id)
1449 {
1450 BlockDriver *drv = bs->drv;
1451 if (!drv)
1452 return -ENOMEDIUM;
1453 if (!drv->bdrv_snapshot_goto)
1454 return -ENOTSUP;
1455 return drv->bdrv_snapshot_goto(bs, snapshot_id);
1456 }
1457
1458 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id)
1459 {
1460 BlockDriver *drv = bs->drv;
1461 if (!drv)
1462 return -ENOMEDIUM;
1463 if (!drv->bdrv_snapshot_delete)
1464 return -ENOTSUP;
1465 return drv->bdrv_snapshot_delete(bs, snapshot_id);
1466 }
1467
1468 int bdrv_snapshot_list(BlockDriverState *bs,
1469 QEMUSnapshotInfo **psn_info)
1470 {
1471 BlockDriver *drv = bs->drv;
1472 if (!drv)
1473 return -ENOMEDIUM;
1474 if (!drv->bdrv_snapshot_list)
1475 return -ENOTSUP;
1476 return drv->bdrv_snapshot_list(bs, psn_info);
1477 }
1478
1479 #define NB_SUFFIXES 4
1480
1481 char *get_human_readable_size(char *buf, int buf_size, int64_t size)
1482 {
1483 static const char suffixes[NB_SUFFIXES] = "KMGT";
1484 int64_t base;
1485 int i;
1486
1487 if (size <= 999) {
1488 snprintf(buf, buf_size, "%" PRId64, size);
1489 } else {
1490 base = 1024;
1491 for(i = 0; i < NB_SUFFIXES; i++) {
1492 if (size < (10 * base)) {
1493 snprintf(buf, buf_size, "%0.1f%c",
1494 (double)size / base,
1495 suffixes[i]);
1496 break;
1497 } else if (size < (1000 * base) || i == (NB_SUFFIXES - 1)) {
1498 snprintf(buf, buf_size, "%" PRId64 "%c",
1499 ((size + (base >> 1)) / base),
1500 suffixes[i]);
1501 break;
1502 }
1503 base = base * 1024;
1504 }
1505 }
1506 return buf;
1507 }
1508
1509 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn)
1510 {
1511 char buf1[128], date_buf[128], clock_buf[128];
1512 #ifdef _WIN32
1513 struct tm *ptm;
1514 #else
1515 struct tm tm;
1516 #endif
1517 time_t ti;
1518 int64_t secs;
1519
1520 if (!sn) {
1521 snprintf(buf, buf_size,
1522 "%-10s%-20s%7s%20s%15s",
1523 "ID", "TAG", "VM SIZE", "DATE", "VM CLOCK");
1524 } else {
1525 ti = sn->date_sec;
1526 #ifdef _WIN32
1527 ptm = localtime(&ti);
1528 strftime(date_buf, sizeof(date_buf),
1529 "%Y-%m-%d %H:%M:%S", ptm);
1530 #else
1531 localtime_r(&ti, &tm);
1532 strftime(date_buf, sizeof(date_buf),
1533 "%Y-%m-%d %H:%M:%S", &tm);
1534 #endif
1535 secs = sn->vm_clock_nsec / 1000000000;
1536 snprintf(clock_buf, sizeof(clock_buf),
1537 "%02d:%02d:%02d.%03d",
1538 (int)(secs / 3600),
1539 (int)((secs / 60) % 60),
1540 (int)(secs % 60),
1541 (int)((sn->vm_clock_nsec / 1000000) % 1000));
1542 snprintf(buf, buf_size,
1543 "%-10s%-20s%7s%20s%15s",
1544 sn->id_str, sn->name,
1545 get_human_readable_size(buf1, sizeof(buf1), sn->vm_state_size),
1546 date_buf,
1547 clock_buf);
1548 }
1549 return buf;
1550 }
1551
1552
1553 /**************************************************************/
1554 /* async I/Os */
1555
1556 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
1557 QEMUIOVector *qiov, int nb_sectors,
1558 BlockDriverCompletionFunc *cb, void *opaque)
1559 {
1560 BlockDriver *drv = bs->drv;
1561 BlockDriverAIOCB *ret;
1562
1563 if (!drv)
1564 return NULL;
1565 if (bdrv_check_request(bs, sector_num, nb_sectors))
1566 return NULL;
1567
1568 ret = drv->bdrv_aio_readv(bs, sector_num, qiov, nb_sectors,
1569 cb, opaque);
1570
1571 if (ret) {
1572 /* Update stats even though technically transfer has not happened. */
1573 bs->rd_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1574 bs->rd_ops ++;
1575 }
1576
1577 return ret;
1578 }
1579
1580 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
1581 QEMUIOVector *qiov, int nb_sectors,
1582 BlockDriverCompletionFunc *cb, void *opaque)
1583 {
1584 BlockDriver *drv = bs->drv;
1585 BlockDriverAIOCB *ret;
1586
1587 if (!drv)
1588 return NULL;
1589 if (bs->read_only)
1590 return NULL;
1591 if (bdrv_check_request(bs, sector_num, nb_sectors))
1592 return NULL;
1593
1594 if (bs->dirty_bitmap) {
1595 set_dirty_bitmap(bs, sector_num, nb_sectors, 1);
1596 }
1597
1598 ret = drv->bdrv_aio_writev(bs, sector_num, qiov, nb_sectors,
1599 cb, opaque);
1600
1601 if (ret) {
1602 /* Update stats even though technically transfer has not happened. */
1603 bs->wr_bytes += (unsigned) nb_sectors * BDRV_SECTOR_SIZE;
1604 bs->wr_ops ++;
1605 }
1606
1607 return ret;
1608 }
1609
1610
1611 typedef struct MultiwriteCB {
1612 int error;
1613 int num_requests;
1614 int num_callbacks;
1615 struct {
1616 BlockDriverCompletionFunc *cb;
1617 void *opaque;
1618 QEMUIOVector *free_qiov;
1619 void *free_buf;
1620 } callbacks[];
1621 } MultiwriteCB;
1622
1623 static void multiwrite_user_cb(MultiwriteCB *mcb)
1624 {
1625 int i;
1626
1627 for (i = 0; i < mcb->num_callbacks; i++) {
1628 mcb->callbacks[i].cb(mcb->callbacks[i].opaque, mcb->error);
1629 qemu_free(mcb->callbacks[i].free_qiov);
1630 qemu_free(mcb->callbacks[i].free_buf);
1631 }
1632 }
1633
1634 static void multiwrite_cb(void *opaque, int ret)
1635 {
1636 MultiwriteCB *mcb = opaque;
1637
1638 if (ret < 0) {
1639 mcb->error = ret;
1640 multiwrite_user_cb(mcb);
1641 }
1642
1643 mcb->num_requests--;
1644 if (mcb->num_requests == 0) {
1645 if (mcb->error == 0) {
1646 multiwrite_user_cb(mcb);
1647 }
1648 qemu_free(mcb);
1649 }
1650 }
1651
1652 static int multiwrite_req_compare(const void *a, const void *b)
1653 {
1654 return (((BlockRequest*) a)->sector - ((BlockRequest*) b)->sector);
1655 }
1656
1657 /*
1658 * Takes a bunch of requests and tries to merge them. Returns the number of
1659 * requests that remain after merging.
1660 */
1661 static int multiwrite_merge(BlockDriverState *bs, BlockRequest *reqs,
1662 int num_reqs, MultiwriteCB *mcb)
1663 {
1664 int i, outidx;
1665
1666 // Sort requests by start sector
1667 qsort(reqs, num_reqs, sizeof(*reqs), &multiwrite_req_compare);
1668
1669 // Check if adjacent requests touch the same clusters. If so, combine them,
1670 // filling up gaps with zero sectors.
1671 outidx = 0;
1672 for (i = 1; i < num_reqs; i++) {
1673 int merge = 0;
1674 int64_t oldreq_last = reqs[outidx].sector + reqs[outidx].nb_sectors;
1675
1676 // This handles the cases that are valid for all block drivers, namely
1677 // exactly sequential writes and overlapping writes.
1678 if (reqs[i].sector <= oldreq_last) {
1679 merge = 1;
1680 }
1681
1682 // The block driver may decide that it makes sense to combine requests
1683 // even if there is a gap of some sectors between them. In this case,
1684 // the gap is filled with zeros (therefore only applicable for yet
1685 // unused space in format like qcow2).
1686 if (!merge && bs->drv->bdrv_merge_requests) {
1687 merge = bs->drv->bdrv_merge_requests(bs, &reqs[outidx], &reqs[i]);
1688 }
1689
1690 if (merge) {
1691 size_t size;
1692 QEMUIOVector *qiov = qemu_mallocz(sizeof(*qiov));
1693 qemu_iovec_init(qiov,
1694 reqs[outidx].qiov->niov + reqs[i].qiov->niov + 1);
1695
1696 // Add the first request to the merged one. If the requests are
1697 // overlapping, drop the last sectors of the first request.
1698 size = (reqs[i].sector - reqs[outidx].sector) << 9;
1699 qemu_iovec_concat(qiov, reqs[outidx].qiov, size);
1700
1701 // We might need to add some zeros between the two requests
1702 if (reqs[i].sector > oldreq_last) {
1703 size_t zero_bytes = (reqs[i].sector - oldreq_last) << 9;
1704 uint8_t *buf = qemu_blockalign(bs, zero_bytes);
1705 memset(buf, 0, zero_bytes);
1706 qemu_iovec_add(qiov, buf, zero_bytes);
1707 mcb->callbacks[i].free_buf = buf;
1708 }
1709
1710 // Add the second request
1711 qemu_iovec_concat(qiov, reqs[i].qiov, reqs[i].qiov->size);
1712
1713 reqs[outidx].nb_sectors += reqs[i].nb_sectors;
1714 reqs[outidx].qiov = qiov;
1715
1716 mcb->callbacks[i].free_qiov = reqs[outidx].qiov;
1717 } else {
1718 outidx++;
1719 reqs[outidx].sector = reqs[i].sector;
1720 reqs[outidx].nb_sectors = reqs[i].nb_sectors;
1721 reqs[outidx].qiov = reqs[i].qiov;
1722 }
1723 }
1724
1725 return outidx + 1;
1726 }
1727
1728 /*
1729 * Submit multiple AIO write requests at once.
1730 *
1731 * On success, the function returns 0 and all requests in the reqs array have
1732 * been submitted. In error case this function returns -1, and any of the
1733 * requests may or may not be submitted yet. In particular, this means that the
1734 * callback will be called for some of the requests, for others it won't. The
1735 * caller must check the error field of the BlockRequest to wait for the right
1736 * callbacks (if error != 0, no callback will be called).
1737 *
1738 * The implementation may modify the contents of the reqs array, e.g. to merge
1739 * requests. However, the fields opaque and error are left unmodified as they
1740 * are used to signal failure for a single request to the caller.
1741 */
1742 int bdrv_aio_multiwrite(BlockDriverState *bs, BlockRequest *reqs, int num_reqs)
1743 {
1744 BlockDriverAIOCB *acb;
1745 MultiwriteCB *mcb;
1746 int i;
1747
1748 if (num_reqs == 0) {
1749 return 0;
1750 }
1751
1752 // Create MultiwriteCB structure
1753 mcb = qemu_mallocz(sizeof(*mcb) + num_reqs * sizeof(*mcb->callbacks));
1754 mcb->num_requests = 0;
1755 mcb->num_callbacks = num_reqs;
1756
1757 for (i = 0; i < num_reqs; i++) {
1758 mcb->callbacks[i].cb = reqs[i].cb;
1759 mcb->callbacks[i].opaque = reqs[i].opaque;
1760 }
1761
1762 // Check for mergable requests
1763 num_reqs = multiwrite_merge(bs, reqs, num_reqs, mcb);
1764
1765 // Run the aio requests
1766 for (i = 0; i < num_reqs; i++) {
1767 acb = bdrv_aio_writev(bs, reqs[i].sector, reqs[i].qiov,
1768 reqs[i].nb_sectors, multiwrite_cb, mcb);
1769
1770 if (acb == NULL) {
1771 // We can only fail the whole thing if no request has been
1772 // submitted yet. Otherwise we'll wait for the submitted AIOs to
1773 // complete and report the error in the callback.
1774 if (mcb->num_requests == 0) {
1775 reqs[i].error = EIO;
1776 goto fail;
1777 } else {
1778 mcb->error = EIO;
1779 break;
1780 }
1781 } else {
1782 mcb->num_requests++;
1783 }
1784 }
1785
1786 return 0;
1787
1788 fail:
1789 free(mcb);
1790 return -1;
1791 }
1792
1793 BlockDriverAIOCB *bdrv_aio_flush(BlockDriverState *bs,
1794 BlockDriverCompletionFunc *cb, void *opaque)
1795 {
1796 BlockDriver *drv = bs->drv;
1797
1798 if (!drv)
1799 return NULL;
1800
1801 /*
1802 * Note that unlike bdrv_flush the driver is reponsible for flushing a
1803 * backing image if it exists.
1804 */
1805 return drv->bdrv_aio_flush(bs, cb, opaque);
1806 }
1807
1808 void bdrv_aio_cancel(BlockDriverAIOCB *acb)
1809 {
1810 acb->pool->cancel(acb);
1811 }
1812
1813
1814 /**************************************************************/
1815 /* async block device emulation */
1816
1817 typedef struct BlockDriverAIOCBSync {
1818 BlockDriverAIOCB common;
1819 QEMUBH *bh;
1820 int ret;
1821 /* vector translation state */
1822 QEMUIOVector *qiov;
1823 uint8_t *bounce;
1824 int is_write;
1825 } BlockDriverAIOCBSync;
1826
1827 static void bdrv_aio_cancel_em(BlockDriverAIOCB *blockacb)
1828 {
1829 BlockDriverAIOCBSync *acb = (BlockDriverAIOCBSync *)blockacb;
1830 qemu_bh_delete(acb->bh);
1831 acb->bh = NULL;
1832 qemu_aio_release(acb);
1833 }
1834
1835 static AIOPool bdrv_em_aio_pool = {
1836 .aiocb_size = sizeof(BlockDriverAIOCBSync),
1837 .cancel = bdrv_aio_cancel_em,
1838 };
1839
1840 static void bdrv_aio_bh_cb(void *opaque)
1841 {
1842 BlockDriverAIOCBSync *acb = opaque;
1843
1844 if (!acb->is_write)
1845 qemu_iovec_from_buffer(acb->qiov, acb->bounce, acb->qiov->size);
1846 qemu_vfree(acb->bounce);
1847 acb->common.cb(acb->common.opaque, acb->ret);
1848 qemu_bh_delete(acb->bh);
1849 acb->bh = NULL;
1850 qemu_aio_release(acb);
1851 }
1852
1853 static BlockDriverAIOCB *bdrv_aio_rw_vector(BlockDriverState *bs,
1854 int64_t sector_num,
1855 QEMUIOVector *qiov,
1856 int nb_sectors,
1857 BlockDriverCompletionFunc *cb,
1858 void *opaque,
1859 int is_write)
1860
1861 {
1862 BlockDriverAIOCBSync *acb;
1863
1864 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
1865 acb->is_write = is_write;
1866 acb->qiov = qiov;
1867 acb->bounce = qemu_blockalign(bs, qiov->size);
1868
1869 if (!acb->bh)
1870 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1871
1872 if (is_write) {
1873 qemu_iovec_to_buffer(acb->qiov, acb->bounce);
1874 acb->ret = bdrv_write(bs, sector_num, acb->bounce, nb_sectors);
1875 } else {
1876 acb->ret = bdrv_read(bs, sector_num, acb->bounce, nb_sectors);
1877 }
1878
1879 qemu_bh_schedule(acb->bh);
1880
1881 return &acb->common;
1882 }
1883
1884 static BlockDriverAIOCB *bdrv_aio_readv_em(BlockDriverState *bs,
1885 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1886 BlockDriverCompletionFunc *cb, void *opaque)
1887 {
1888 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 0);
1889 }
1890
1891 static BlockDriverAIOCB *bdrv_aio_writev_em(BlockDriverState *bs,
1892 int64_t sector_num, QEMUIOVector *qiov, int nb_sectors,
1893 BlockDriverCompletionFunc *cb, void *opaque)
1894 {
1895 return bdrv_aio_rw_vector(bs, sector_num, qiov, nb_sectors, cb, opaque, 1);
1896 }
1897
1898 static BlockDriverAIOCB *bdrv_aio_flush_em(BlockDriverState *bs,
1899 BlockDriverCompletionFunc *cb, void *opaque)
1900 {
1901 BlockDriverAIOCBSync *acb;
1902
1903 acb = qemu_aio_get(&bdrv_em_aio_pool, bs, cb, opaque);
1904 acb->is_write = 1; /* don't bounce in the completion hadler */
1905 acb->qiov = NULL;
1906 acb->bounce = NULL;
1907 acb->ret = 0;
1908
1909 if (!acb->bh)
1910 acb->bh = qemu_bh_new(bdrv_aio_bh_cb, acb);
1911
1912 bdrv_flush(bs);
1913 qemu_bh_schedule(acb->bh);
1914 return &acb->common;
1915 }
1916
1917 /**************************************************************/
1918 /* sync block device emulation */
1919
1920 static void bdrv_rw_em_cb(void *opaque, int ret)
1921 {
1922 *(int *)opaque = ret;
1923 }
1924
1925 #define NOT_DONE 0x7fffffff
1926
1927 static int bdrv_read_em(BlockDriverState *bs, int64_t sector_num,
1928 uint8_t *buf, int nb_sectors)
1929 {
1930 int async_ret;
1931 BlockDriverAIOCB *acb;
1932 struct iovec iov;
1933 QEMUIOVector qiov;
1934
1935 async_context_push();
1936
1937 async_ret = NOT_DONE;
1938 iov.iov_base = (void *)buf;
1939 iov.iov_len = nb_sectors * 512;
1940 qemu_iovec_init_external(&qiov, &iov, 1);
1941 acb = bdrv_aio_readv(bs, sector_num, &qiov, nb_sectors,
1942 bdrv_rw_em_cb, &async_ret);
1943 if (acb == NULL) {
1944 async_ret = -1;
1945 goto fail;
1946 }
1947
1948 while (async_ret == NOT_DONE) {
1949 qemu_aio_wait();
1950 }
1951
1952
1953 fail:
1954 async_context_pop();
1955 return async_ret;
1956 }
1957
1958 static int bdrv_write_em(BlockDriverState *bs, int64_t sector_num,
1959 const uint8_t *buf, int nb_sectors)
1960 {
1961 int async_ret;
1962 BlockDriverAIOCB *acb;
1963 struct iovec iov;
1964 QEMUIOVector qiov;
1965
1966 async_context_push();
1967
1968 async_ret = NOT_DONE;
1969 iov.iov_base = (void *)buf;
1970 iov.iov_len = nb_sectors * 512;
1971 qemu_iovec_init_external(&qiov, &iov, 1);
1972 acb = bdrv_aio_writev(bs, sector_num, &qiov, nb_sectors,
1973 bdrv_rw_em_cb, &async_ret);
1974 if (acb == NULL) {
1975 async_ret = -1;
1976 goto fail;
1977 }
1978 while (async_ret == NOT_DONE) {
1979 qemu_aio_wait();
1980 }
1981
1982 fail:
1983 async_context_pop();
1984 return async_ret;
1985 }
1986
1987 void bdrv_init(void)
1988 {
1989 module_call_init(MODULE_INIT_BLOCK);
1990 }
1991
1992 void bdrv_init_with_whitelist(void)
1993 {
1994 use_bdrv_whitelist = 1;
1995 bdrv_init();
1996 }
1997
1998 void *qemu_aio_get(AIOPool *pool, BlockDriverState *bs,
1999 BlockDriverCompletionFunc *cb, void *opaque)
2000 {
2001 BlockDriverAIOCB *acb;
2002
2003 if (pool->free_aiocb) {
2004 acb = pool->free_aiocb;
2005 pool->free_aiocb = acb->next;
2006 } else {
2007 acb = qemu_mallocz(pool->aiocb_size);
2008 acb->pool = pool;
2009 }
2010 acb->bs = bs;
2011 acb->cb = cb;
2012 acb->opaque = opaque;
2013 return acb;
2014 }
2015
2016 void qemu_aio_release(void *p)
2017 {
2018 BlockDriverAIOCB *acb = (BlockDriverAIOCB *)p;
2019 AIOPool *pool = acb->pool;
2020 acb->next = pool->free_aiocb;
2021 pool->free_aiocb = acb;
2022 }
2023
2024 /**************************************************************/
2025 /* removable device support */
2026
2027 /**
2028 * Return TRUE if the media is present
2029 */
2030 int bdrv_is_inserted(BlockDriverState *bs)
2031 {
2032 BlockDriver *drv = bs->drv;
2033 int ret;
2034 if (!drv)
2035 return 0;
2036 if (!drv->bdrv_is_inserted)
2037 return 1;
2038 ret = drv->bdrv_is_inserted(bs);
2039 return ret;
2040 }
2041
2042 /**
2043 * Return TRUE if the media changed since the last call to this
2044 * function. It is currently only used for floppy disks
2045 */
2046 int bdrv_media_changed(BlockDriverState *bs)
2047 {
2048 BlockDriver *drv = bs->drv;
2049 int ret;
2050
2051 if (!drv || !drv->bdrv_media_changed)
2052 ret = -ENOTSUP;
2053 else
2054 ret = drv->bdrv_media_changed(bs);
2055 if (ret == -ENOTSUP)
2056 ret = bs->media_changed;
2057 bs->media_changed = 0;
2058 return ret;
2059 }
2060
2061 /**
2062 * If eject_flag is TRUE, eject the media. Otherwise, close the tray
2063 */
2064 int bdrv_eject(BlockDriverState *bs, int eject_flag)
2065 {
2066 BlockDriver *drv = bs->drv;
2067 int ret;
2068
2069 if (bs->locked) {
2070 return -EBUSY;
2071 }
2072
2073 if (!drv || !drv->bdrv_eject) {
2074 ret = -ENOTSUP;
2075 } else {
2076 ret = drv->bdrv_eject(bs, eject_flag);
2077 }
2078 if (ret == -ENOTSUP) {
2079 if (eject_flag)
2080 bdrv_close(bs);
2081 ret = 0;
2082 }
2083
2084 return ret;
2085 }
2086
2087 int bdrv_is_locked(BlockDriverState *bs)
2088 {
2089 return bs->locked;
2090 }
2091
2092 /**
2093 * Lock or unlock the media (if it is locked, the user won't be able
2094 * to eject it manually).
2095 */
2096 void bdrv_set_locked(BlockDriverState *bs, int locked)
2097 {
2098 BlockDriver *drv = bs->drv;
2099
2100 bs->locked = locked;
2101 if (drv && drv->bdrv_set_locked) {
2102 drv->bdrv_set_locked(bs, locked);
2103 }
2104 }
2105
2106 /* needed for generic scsi interface */
2107
2108 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf)
2109 {
2110 BlockDriver *drv = bs->drv;
2111
2112 if (drv && drv->bdrv_ioctl)
2113 return drv->bdrv_ioctl(bs, req, buf);
2114 return -ENOTSUP;
2115 }
2116
2117 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
2118 unsigned long int req, void *buf,
2119 BlockDriverCompletionFunc *cb, void *opaque)
2120 {
2121 BlockDriver *drv = bs->drv;
2122
2123 if (drv && drv->bdrv_aio_ioctl)
2124 return drv->bdrv_aio_ioctl(bs, req, buf, cb, opaque);
2125 return NULL;
2126 }
2127
2128
2129
2130 void *qemu_blockalign(BlockDriverState *bs, size_t size)
2131 {
2132 return qemu_memalign((bs && bs->buffer_alignment) ? bs->buffer_alignment : 512, size);
2133 }
2134
2135 void bdrv_set_dirty_tracking(BlockDriverState *bs, int enable)
2136 {
2137 int64_t bitmap_size;
2138
2139 if (enable) {
2140 if (!bs->dirty_bitmap) {
2141 bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
2142 BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
2143 bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
2144
2145 bs->dirty_bitmap = qemu_mallocz(bitmap_size);
2146 }
2147 } else {
2148 if (bs->dirty_bitmap) {
2149 qemu_free(bs->dirty_bitmap);
2150 bs->dirty_bitmap = NULL;
2151 }
2152 }
2153 }
2154
2155 int bdrv_get_dirty(BlockDriverState *bs, int64_t sector)
2156 {
2157 int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
2158
2159 if (bs->dirty_bitmap &&
2160 (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bs)) {
2161 return bs->dirty_bitmap[chunk / (sizeof(unsigned long) * 8)] &
2162 (1 << (chunk % (sizeof(unsigned long) * 8)));
2163 } else {
2164 return 0;
2165 }
2166 }
2167
2168 void bdrv_reset_dirty(BlockDriverState *bs, int64_t cur_sector,
2169 int nr_sectors)
2170 {
2171 set_dirty_bitmap(bs, cur_sector, nr_sectors, 0);
2172 }
kraxel's qemu bits